This isn't really omegaverse. In this story there are people called pregmen (I think) who have the ability to get pregnant. This is about two highschool boys and one of them hides the fact that he is a pregman.
You may feel your favorite manga should be gathered together into distinct categories for your own reference and, now, you can do this with a LIST. After you've created your list or lists, you can proudly recommend them to other manga fans to showcase and share your taste in manga.
Nindan - Danshikou de Ninshin Shita Ore